The present invention relates to a mullion-type curtain wall or curtain wall having a mullion structure in which mullions are fixed to a structural body of building, for example, such as concrete floor slab, steel framed truss or the like, transoms are stretched between adjacent mullions respectively, and an open-close type window or glass window is mounted to a space defined by the adjacent two mullions and the transoms stretched therebetween.
There is known as a curtain wall having a mullion structure, such as disclosed in Japanese Utility Model Publication No. HEI 2-33536, in which a plurality of transoms are connected between bilateral right and left mullions to define a space therebetween for mounting a window structure, and vertical frame members are attached between upper and lower transoms of the bilateral mullions to thereby form a rectangular frame by the upper and lower transoms and the bilateral vertical frame members. A sash is fitted to the frame thus formed to be opened and closed, constituting a sash unit.
According to the conventional curtain wall having the mullion structure mentioned above, the sash unit must be assembled at a construction site by connecting the transoms to the mullions, mounting the transoms to the vertical frames and fitting the sash to the frame thus formed, providing a troublesome assembling workings and being inconvenient.